2 * ustream - library for stream buffer management
4 * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
27 static void ustream_init_buf(struct ustream_buf
*buf
, int len
)
32 memset(buf
, 0, sizeof(*buf
));
33 buf
->data
= buf
->tail
= buf
->head
;
34 buf
->end
= buf
->head
+ len
;
38 static void ustream_add_buf(struct ustream_buf_list
*l
, struct ustream_buf
*buf
)
49 l
->data_tail
= l
->head
;
52 static bool ustream_can_alloc(struct ustream_buf_list
*l
)
54 if (l
->max_buffers
<= 0)
57 return (l
->buffers
< l
->max_buffers
);
60 static int ustream_alloc_default(struct ustream
*s
, struct ustream_buf_list
*l
)
62 struct ustream_buf
*buf
;
64 if (!ustream_can_alloc(l
))
67 buf
= malloc(sizeof(*buf
) + l
->buffer_len
+ s
->string_data
);
68 ustream_init_buf(buf
, l
->buffer_len
);
69 ustream_add_buf(l
, buf
);
74 static void ustream_free_buffers(struct ustream_buf_list
*l
)
76 struct ustream_buf
*buf
= l
->head
;
79 struct ustream_buf
*next
= buf
->next
;
89 void ustream_free(struct ustream
*s
)
94 uloop_timeout_cancel(&s
->state_change
);
95 ustream_free_buffers(&s
->r
);
96 ustream_free_buffers(&s
->w
);
99 static void ustream_state_change_cb(struct uloop_timeout
*t
)
101 struct ustream
*s
= container_of(t
, struct ustream
, state_change
);
104 ustream_free_buffers(&s
->w
);
109 void ustream_init_defaults(struct ustream
*s
)
111 #define DEFAULT_SET(_f, _default) \
117 DEFAULT_SET(s
->r
.alloc
, ustream_alloc_default
);
118 DEFAULT_SET(s
->w
.alloc
, ustream_alloc_default
);
120 DEFAULT_SET(s
->r
.min_buffers
, 1);
121 DEFAULT_SET(s
->r
.max_buffers
, 1);
122 DEFAULT_SET(s
->r
.buffer_len
, 4096);
124 DEFAULT_SET(s
->w
.min_buffers
, 2);
125 DEFAULT_SET(s
->w
.max_buffers
, -1);
126 DEFAULT_SET(s
->w
.buffer_len
, 256);
130 s
->state_change
.cb
= ustream_state_change_cb
;
131 s
->write_error
= false;
133 s
->eof_write_done
= false;
143 static bool ustream_should_move(struct ustream_buf_list
*l
, struct ustream_buf
*buf
, int len
)
148 /* nothing to squeeze */
149 if (buf
->data
== buf
->head
)
152 maxlen
= buf
->end
- buf
->head
;
153 offset
= buf
->data
- buf
->head
;
155 /* less than half is available */
156 if (offset
> maxlen
/ 2)
159 /* less than 32 bytes data but takes more than 1/4 space */
160 if (buf
->tail
- buf
->data
< 32 && offset
> maxlen
/ 4)
163 /* more buf is already in list or can be allocated */
164 if (buf
!= l
->tail
|| ustream_can_alloc(l
))
167 /* no need to move if len is available at the tail */
168 return (buf
->end
- buf
->tail
< len
);
171 static void ustream_free_buf(struct ustream_buf_list
*l
, struct ustream_buf
*buf
)
176 if (buf
== l
->data_tail
)
177 l
->data_tail
= buf
->next
;
182 if (--l
->buffers
>= l
->min_buffers
) {
188 ustream_init_buf(buf
, buf
->end
- buf
->head
);
189 ustream_add_buf(l
, buf
);
192 static void __ustream_set_read_blocked(struct ustream
*s
, unsigned char val
)
194 bool changed
= !!s
->read_blocked
!= !!val
;
196 s
->read_blocked
= val
;
198 s
->set_read_blocked(s
);
201 void ustream_set_read_blocked(struct ustream
*s
, bool set
)
203 unsigned char val
= s
->read_blocked
& ~READ_BLOCKED_USER
;
206 val
|= READ_BLOCKED_USER
;
208 __ustream_set_read_blocked(s
, val
);
211 void ustream_consume(struct ustream
*s
, int len
)
213 struct ustream_buf
*buf
= s
->r
.head
;
218 s
->r
.data_bytes
-= len
;
219 if (s
->r
.data_bytes
< 0)
223 struct ustream_buf
*next
= buf
->next
;
224 int buf_len
= buf
->tail
- buf
->data
;
232 ustream_free_buf(&s
->r
, buf
);
236 __ustream_set_read_blocked(s
, s
->read_blocked
& ~READ_BLOCKED_FULL
);
239 static void ustream_fixup_string(struct ustream
*s
, struct ustream_buf
*buf
)
247 static bool ustream_prepare_buf(struct ustream
*s
, struct ustream_buf_list
*l
, int len
)
249 struct ustream_buf
*buf
;
253 if (ustream_should_move(l
, buf
, len
)) {
254 int len
= buf
->tail
- buf
->data
;
256 memmove(buf
->head
, buf
->data
, len
);
257 buf
->data
= buf
->head
;
258 buf
->tail
= buf
->data
+ len
;
261 ustream_fixup_string(s
, buf
);
263 /* some chunks available at the tail */
264 if (buf
->tail
!= buf
->end
)
266 /* next buf available */
268 l
->data_tail
= buf
->next
;
273 if (!ustream_can_alloc(l
))
276 if (l
->alloc(s
, l
) < 0)
279 l
->data_tail
= l
->tail
;
283 char *ustream_reserve(struct ustream
*s
, int len
, int *maxlen
)
285 struct ustream_buf
*buf
;
287 if (!ustream_prepare_buf(s
, &s
->r
, len
)) {
288 __ustream_set_read_blocked(s
, s
->read_blocked
| READ_BLOCKED_FULL
);
293 buf
= s
->r
.data_tail
;
294 *maxlen
= buf
->end
- buf
->tail
;
298 void ustream_fill_read(struct ustream
*s
, int len
)
300 struct ustream_buf
*buf
= s
->r
.data_tail
;
304 s
->r
.data_bytes
+= len
;
309 maxlen
= buf
->end
- buf
->tail
;
315 ustream_fixup_string(s
, buf
);
317 s
->r
.data_tail
= buf
;
322 s
->notify_read(s
, n
);
325 char *ustream_get_read_buf(struct ustream
*s
, int *buflen
)
331 len
= s
->r
.head
->tail
- s
->r
.head
->data
;
333 data
= s
->r
.head
->data
;
342 int ustream_read(struct ustream
*s
, char *buf
, int buflen
)
349 chunk
= ustream_get_read_buf(s
, &chunk_len
);
352 if (chunk_len
> buflen
- len
)
353 chunk_len
= buflen
- len
;
354 memcpy(buf
+ len
, chunk
, chunk_len
);
355 ustream_consume(s
, chunk_len
);
357 } while (len
< buflen
);
362 static void ustream_write_error(struct ustream
*s
)
365 ustream_state_change(s
);
366 s
->write_error
= true;
369 bool ustream_write_pending(struct ustream
*s
)
371 struct ustream_buf
*buf
= s
->w
.head
;
377 while (buf
&& s
->w
.data_bytes
) {
378 struct ustream_buf
*next
= buf
->next
;
379 int maxlen
= buf
->tail
- buf
->data
;
381 len
= s
->write(s
, buf
->data
, maxlen
, !!buf
->next
);
383 ustream_write_error(s
);
391 s
->w
.data_bytes
-= len
;
397 ustream_free_buf(&s
->w
, buf
);
402 s
->notify_write(s
, wr
);
404 if (s
->eof
&& wr
&& !s
->w
.data_bytes
)
405 ustream_state_change(s
);
407 return !s
->w
.data_bytes
;
410 static int ustream_write_buffered(struct ustream
*s
, const char *data
, int len
, int wr
)
412 struct ustream_buf_list
*l
= &s
->w
;
413 struct ustream_buf
*buf
;
417 if (!ustream_prepare_buf(s
, &s
->w
, len
))
422 maxlen
= buf
->end
- buf
->tail
;
426 memcpy(buf
->tail
, data
, maxlen
);
431 l
->data_bytes
+= maxlen
;
437 int ustream_write(struct ustream
*s
, const char *data
, int len
, bool more
)
439 struct ustream_buf_list
*l
= &s
->w
;
445 if (!l
->data_bytes
) {
446 wr
= s
->write(s
, data
, len
, more
);
451 ustream_write_error(s
);
459 return ustream_write_buffered(s
, data
, len
, wr
);
462 #define MAX_STACK_BUFLEN 256
464 int ustream_vprintf(struct ustream
*s
, const char *format
, va_list arg
)
466 struct ustream_buf_list
*l
= &s
->w
;
469 int wr
, maxlen
, buflen
;
474 if (!l
->data_bytes
) {
475 buf
= alloca(MAX_STACK_BUFLEN
);
477 maxlen
= vsnprintf(buf
, MAX_STACK_BUFLEN
, format
, arg2
);
479 if (maxlen
< MAX_STACK_BUFLEN
) {
480 wr
= s
->write(s
, buf
, maxlen
, false);
482 ustream_write_error(s
);
490 return ustream_write_buffered(s
, buf
, maxlen
, wr
);
492 buf
= malloc(maxlen
+ 1);
493 wr
= vsnprintf(buf
, maxlen
+ 1, format
, arg
);
494 wr
= ustream_write(s
, buf
, wr
, false);
500 if (!ustream_prepare_buf(s
, l
, 1))
503 buf
= l
->data_tail
->tail
;
504 buflen
= l
->data_tail
->end
- buf
;
507 maxlen
= vsnprintf(buf
, buflen
, format
, arg2
);
514 l
->data_tail
->tail
+= wr
;
519 buf
= malloc(maxlen
+ 1);
520 maxlen
= vsnprintf(buf
, maxlen
+ 1, format
, arg
);
521 wr
= ustream_write_buffered(s
, buf
+ wr
, maxlen
- wr
, wr
);
527 int ustream_printf(struct ustream
*s
, const char *format
, ...)
535 va_start(arg
, format
);
536 ret
= ustream_vprintf(s
, format
, arg
);